Historic Heatwave Persists in the Southwest as California Community Matches All-Time March Temperature Record

In the small desert enclave of North Shore, California, temperatures soared to an astounding 108 degrees Fahrenheit (42.2 Celsius) one day, equaling a record for the highest March temperature ever documented in the United States. This climatic feat, previously achieved by Rio Grande City, Texas, in 1954, signals an alarming trend of record-breaking winter heat that forecasters predict will persist across the Southwest through the weekend.

Neighboring the aptly named town of Thermal, located in the desert northeast of San Diego, North Shore is expected to continue experiencing extreme temperatures, with forecasts predicting a scorching 110 degrees Fahrenheit (43.3 Celsius) by Friday.

Meanwhile, in Arizona, the heat has shown little mercy even after sunset. Phoenix registered a record-high overnight low of 69 degrees Fahrenheit (20.5 Celsius) on March 19, according to the National Weather Service. Daytime temperatures in Phoenix are expected to climb to around 105 degrees Fahrenheit (40.5 Celsius) on Thursday, with the potential for even hotter conditions on Friday. “For some perspective, the average first 105-degree day of the year normally occurs on May 22nd,” the weather service remarked, highlighting the unusual nature of this heatwave. The last instance of Phoenix witnessing triple-digit temperatures in March was nearly four decades ago.

Across the region, several cities shattered records for March heat, experiencing their hottest March days in 40 years. In Las Vegas, temperatures reached a sweltering 99 degrees Fahrenheit (37.2 Celsius), eclipsing its previous March record of 93 degrees Fahrenheit (33.8 Celsius) set in 2022.

Las Vegas hit 99 (37.2 C) degrees, smashing its March record, which was 93 (33.8 C) degrees in 2022.

Downtown Los Angeles reached 94 (34.4 C) degrees, beating its previous daily high of 87 (30.5) degrees in 1997.

And the desert destination of Palm Springs, California, was 104 (40 C) degrees, tying its hottest March day on record from 1966.

It will continue to be 20 to 30 degrees above normal March temperatures for the rest of the week in the Southwest before the mercury drops slightly starting Sunday. Many other cities in the region are expected to see their earliest 100-plus (37.8-plus C) degree day on record, according to the weather service.